The mesoporous and nanorods SnO2 are synthesized by controlling the state of SnCl2·2H2O precursor with SBA-15 as hard template, and the possible formation mechanisms at different assembling modes inside the ordered mesoporous silica templates are proposed. In addition, SnO2 nanoparticles are synthesized by hydrolysis depositing method. The electrochemical tests of as-prepared samples indicate that the reticular stacking structure of the nanorods would limit the Li+ ions to intercalate, but the effect of volume expansion in this case upon cycling is insignificant. The mesostructure SnO2 tends to be stable after partial structural collapse at first few cycles. And the Li+ ions can readily intercalate and de-intercalate into/from its ordered channels structure, which provides a high capacity and an improved cycle property. Although SnO2 nanoparticles deliver high capacity at an early stage, the agglomeration may induce the capacity to drop rapidly after a certain number of cycles.

In the work, an in situ chemical synthesis approach has been developed to fabricate SnO2/reduced graphene oxide nanocomposites in ethanol solution. X-ray diffraction, x-ray photoelectron, Fourier transform infrared and Raman spectrum revealed the formation of SnO2/reduced graphene oxide nanocomposites. Scanning electron microscopy and transmission electron microscopy showed that SnO2 nanoparticles had a crystal size of about 3–4 nm and homogeneously distributed on reduced graphene oxide matrix. The electrochemical performances of the SnO2/reduced graphene oxide nanocomposites as anode materials were measured by the galvanostatic charge/discharge cycling. The results indicated that as-synthesized SnO2/reduced graphene oxide nanocomposites had a reversible lithium storage capacity of 1051 mAh/g and an enhanced cyclability, which can be attributed to increased electrode conductivity and buffer effect to volume change in the presence of a percolated reduced graphene oxide network embedded into the metal oxide electrodes.

The present work investigates inorganic–organic nanocomposite polymer electrolytes (NCPEs) for lithium-ion battery applications. Nanoscale TiO2 particles were dispersed into boron comprising poly(vinyl alcohol) (PVA)-g-poly(ethylene glycol) methyl ether (PEGME) host polymer at several percentages. During preparation, nanocomposite matrices were doped with CF3SO3Li at several compositions and homogeneous soft solid materials were obtained. The interactions between host copolymer and inorganic additive and dopant were studied by Fourier transform infrared spectroscopy. The surface morphology of the NCPEs was investigated by scanning electron microscopy and their thermal properties were studied by thermogravimetric analysis and differential scanning calorimetry. The ionic conductivity of these novel NCPEs was studied by dielectric-impedance spectroscopy. High ambient temperature Li+ ion conducting (∼10−4 S/cm) NCPE matrices can be suggested for lithium battery applications.

Highly luminescent CdTe quantum dots (QDs) were prepared through a fast, facile, and straightforward method. The crystal structure, particle size, optical properties as well as molecular interactions between the CdTe QDs and their capping agents have been investigated by high resolution transmission electron microscopy, selected area electron diffraction, scanning transmission electron microscope–energy dispersive x-ray spectroscopy, UV-vis absorption, photoluminescence, and Fourier transform infrared, respectively. The results illustrate that the CdTe nanoparticles exhibit cubic structure and the average crystallite size is 2.3 nm. Meanwhile, fluorescence and UV-vis spectroscopic techniques were used to study the interaction between hemin and the well-defined CdTe QDs. In weak basic media, the fluorescence of CdTe QDs was quenched notably by hemin, and the quenching values were proportional to the concentration of the quencher in a certain range. The quenching mechanism was discussed to be a dynamic quenching procedure, collisional process, and hemin as a fluorescence quencher donated its electron to CdTe QDs to occupy the hole and accordingly disrupted the electron–hole recombination.

Bi2O2CO3/ZnWO4 composite photocatalysts have been successfully synthesized by a mixed calcination method after hydrothermal process. The catalysts were characterized by powder x-ray diffraction, scanning electron microscopy, transmission electron microscopy, high resolution transmission electron microscopy, x-ray photoelectron spectroscopy, and UV-vis diffuse reflectance spectrum. The results showed that the hierarchical Bi2O2CO3/ZnWO4 nanocomposites were obtained by mixed grinding calcination method and Bi2O2CO3 nanospheres grow on the primary ZnWO4 particles. The Bi2O2CO3/ZnWO4 composites exhibit higher photocatalytic activities compared to pure ZnWO4 and Bi2O2CO3 particles under UV light irradiation. Furthermore, the excellent photocatalytic efficiency of the Bi2O2CO3/ZnWO4 composite was deduced closely related to Bi2O2CO3/ZnWO4 heterojunctions whose presence is generally regarded to be a favorable factor for the separation of photogenerated electrons and holes.

A simple one-pot hydrothermal approach that allowed the selective synthesis of complex ZnO architectures with varying configurations without using any surfactants and/or solid templates is proposed in this paper. The ZnO configurations include spherical aggregates, nanosheet-based flowers, microrod-composed flowers, and nanopetal-built flowers. Kinetic factors (i.e., the base type and base/Zn2+ molar ratio) can be easily utilized to control the oriented attachment and growth of [Zn(OH)]2− on the (001) polar planes, thereby regulating the morphology of ZnO architectures. The ZnO architectures were characterized by scanning electron microscopy, transmission electron microscopy, selected-area electron diffraction, x-ray diffraction, and specific surface area. The relationships between the structures and microwave electromagnetic properties were established. Enhanced dielectric and absorption properties were exhibited by ZnO flowers composed of large-aspect-ratio microrods. Such properties could be attributed to the improved microcurrent attenuation and interface scattering rather than the dielectric relaxation and microantenna radiation. This study provides a guide for creating and synthesizing highly efficient microwave absorbing materials.

Multiferroic CoFe2O4–BiFeO3 (CFO–BFO) core–shell nanofibers were synthesized by coaxial electrospinning. The spinel structure of CFO and perovskite structure of BFO were confirmed by x-ray diffraction and high-resolution transmission electron microscopy. The core–shell configuration of nanofibers was verified by scanning electron microscopy and transmission electron microscopy images. The macroscopic ferromagnetic property of core–shell nanofibers was demonstrated by magnetic hysteresis loop. The local magnetoelectric (ME) coupling was confirmed by using dual frequency piezoresponse force microscopy (PFM) under an external magnetic field, showing magnetically induced evolution of piezoresponse and domain structure. The ferroelectric characteristics are demonstrated by the switching spectroscopy PFM. From PFM hysteresis and butterfly loops, it is observed that the piezoresponse amplitude is reduced while coercive voltage increased under external in-plane magnetic field, induced through the mechanical interactions between magnetostrictive CFO and piezoelectric BFO, from which the lateral ME coupling can be estimated quantitatively. The nanofibers thus can find a variety of applications as a one-dimensional multiferroic material.

Nanoparticles of ∼55 nm in diameter have been found to significantly increase the fracture toughness of nanocomposites with a ductile polymer matrix. This paper presents a comparative study of the effectiveness of micrometer-sized and nanosized elastomeric particles in improving the fracture toughness and strength of polymeric adhesives. Particular focuses are on the effects of particle size, matrix ductility, and adhesive thickness on the shear strength and fracture toughness. The results reveal that for an epoxy adhesive cured with a J400 hardener, nanosized particles can produce nearly 18 times more increase in fracture toughness than what can be achieved using micrometer-sized particles at the same volume fraction of 5.0 vol%. This huge improvement of adhesives' fracture toughness by nanosized particles is similar to that observed in bulk nanocomposites, indicating that the superior toughening mechanism of nanosized elastomeric particles is equally effective in thin adhesives constrained by stiff adherends.

New organic/inorganic mesoporous luminescent hybrid materials containing lanthanide (Eu, Tb) complexes chemically bonded to mesoporous SBA-15 [a kind of mesoporous silica with two-dimensional hexagonal (P6mm) structure] have been successfully synthesized by co-condensation of the modified hexafluoroacetylacetone (HFAASi) and tetraethoxysilane (TEOS) in the presence of Pluronic P123 surfactant as a template. The luminescent properties of these resulting mesoporous hybrid materials [denoted as Ln(HFAASi-SBA-15)3phen, Ln = Eu, Tb; phen = 1,10-phenanthroline] were characterized by Fourier transform infrared, small-angle powder x-ray diffraction, N2 adsorption measurements, transmission electron microscope, ultraviolet-visible diffuse reflection absorption spectra, and photoluminescent spectra, and the results exhibit that they all have uniformity in mesostructure and high surface area. Moreover, the mesoporous hybrid materials Eu(HFAASi-SBA-15)3phen and Tb(HFAASi-SBA-15)3phen exhibit the characteristic luminescence of Eu3+ and Tb3+, respectively, indicating that the effective intramolecular energy transfer between HFAASi and the lanthanide ions has been achieved.

In this study, 3 mol% Y2O3-stabilized zirconia (3Y–ZrO2) and commercially pure titanium (cp-Ti) joints were fabricated with an Ag68.8Cu26.7Ti4.5 interlayer (Ticusil) at 900 °C for various brazing periods. After brazing at 900 °C/0.1 h, Ti2Cu, TiCu, Ti3Cu4, and TiCu4 layers were present at the Ti/Ticusil interface, while TiCu and TiO layers were observed at the Ticusil/3Y–ZrO2 interface. In the residual interlayer, clumpy TiCu4 was formed along with the Ag solid phase. After brazing at 900 °C/1 h, Ti3Cu3O and Ti2O layers were formed at the interlayer/ZrO2 interface, while Cu2O was precipitated in the residual interlayer with $\left[ {111} \right]_{{\rm{Cu}}_{\rm{2}} {\rm{O}}} //\left[ {111} \right]_{{\rm{Ag}}}$ and $\left( {20\bar 2} \right)_{{\rm{Cu}}_{\rm{2}} {\rm{O}}} //\left( {20\bar 2} \right){}_{{\rm{Ag}}}$. After brazing at 900 °C/6 h, a two-phase (α-Ti + Ti2Cu) region was observed on the Ti side with $\left[ {2\bar 1\bar 10} \right]_{{\rm{\alpha - Ti}}} //\left[ {100} \right]_{{\rm{Ti}}_{\rm{2}} {\rm{Cu}}}$ and $\left( {0002} \right)_{{\rm{\alpha - Ti}}} //\left( {0\bar 13} \right)_{{\rm{Ti}}_{\rm{2}} {\rm{Cu}}}$, while the TiCu layer grew at the expense of Ti3Cu4 and TiCu4. The bonding mechanisms and diffusion paths were explored with the aid of Ag–Cu–Ti and Ti–Cu–O ternary phase diagrams.

In this study, we obtain true stress–strain (SS) curves for a sheet specimen under consideration of local necking and material anisotropy. We first extract the SS curve up to the diffuse necking point from the tensile test load–displacement data. The curve's part after the onset of diffuse necking is extrapolated by the weighted-average method proposed by Ling [Y. Ling, AMP J. Technol. 5, 37–48 (1996)]. Initiation of local necking is predicted by means of the minor-to-major strain ratio in the specimen's center. We propose a criterion to determine the strain ratio at the onset of local necking and the major strain corresponding to the strain ratio at local necking. We complete the true SS curve by cutting off the SS curve at the major strains corresponding to the local necking or apparent fracture point. Finally, the effects of material anisotropy on SS curves are discussed.

High strength aluminum (Al) alloys were prepared by rapid solidification method in the Al–Ni–La system. Microstructural characterizations show that all the investigated Al–Ni–La alloys are comprised of Al, rod-like Al3Ni, and blocky Al11La3 phases, of which the size and volume fraction are composition-dependent. The Al85.5Ni9.5La5 (at.%) alloy shows the finest microstructure, which contributes to the highest strength along with considerable plasticity. The experimental analysis and finite element simulation (FES) show that the distribution of the intermetallic phases greatly affects the mechanical properties of the alloys. The rod-like Al3Ni phase precipitated with the locally uniform direction prevents the propagation of cracks and benefits the plastic deformation, whereas the blocky Al11La3 phase exhibits the nature of brittleness and acts as the origin of the microcrack initiation. These findings suggest a new method to design high strength Al alloys.

Knowledge of the plasticity associated with the incipient stage of chip formation is useful toward developing an understanding of the deformation field underlying severe plastic deformation processes. The transition from a transient state of straining to a steady state was investigated in plane strain machining of a model material system—copper. Characterization of the evolution to a steady-state deformation field was made by image correlation, hardness mapping, load analysis, and microstructure characterization. Empirical relationships relating the deformation heterogeneity and the process parameters were found and explained by the corresponding effects on shear plane geometry. The results are potentially useful to facilitate a framework for process design of large strain deformation configurations, wherein transient deformation fields prevail. These implications are considered in the present study to quantify the efficiency of processing methods for bulk ultrafine-grained metals by large strain extrusion machining and equal channel angular pressing.